Jqt prefeTi-\}ing the Gafes fcparate. 1^^ 



tion. When there is a quick and plentiful l"uj>ply of gas, 

 the whole of the liquid is kept in continual motion, offevintr 

 therehv a proportionally large fiirface for impregnation, when 

 that is the obiec^l in view ; as when it is wiilicd, for indance, 

 to impregnate water very highly with ammoniaral gas pro- 

 cured from the fulpliate or muriate of ammonia bv lime. 

 7'he quantity of liquid empioved at one time in the adaptors 

 fliould be about fufficient to fill the loueil one full, and the 

 middle one about a third nart. 



The apparatus of wiiicii I have been fpeaking, which is 

 lefs expenlive than ground woulfes, not fo ealily injured, 

 ftnd more readily replaced when any part is fractured, I have 

 found fo extremely ufcful, and applicable to fo many pur- 

 pofes, that I perfuade mylelf fueh a defcription of it as wiSl 

 enable any oue to s;ct it con drafted, will be acceptable to 

 many. United with a fcries of woulfes, it forms one oi the 

 completeft apparatuses tliat has yet been deviled for a great 

 variety of chemical experiments ; for it is not propofed t» 

 fupeifede the woulfes : indeed, when galeous produtits are 

 intended to l)e pafi'ed through a variety of liquids, they will, 

 in many cafes, be found indifpenfably requilite *. I fliall 

 take the prefent opportunity, now that we are fpcaking of 

 W'oiilfc's a|)paratns, of mentioning a few eircumftances 

 which, having found ufeful mvfelf in conitrucling a ferie* 

 of woulfes, may pr;)ve equally fo to C/fheis. 



Lavoifier frequently regretted ihc wantof aperfeft Woulfc's 

 apparatus, the ufual method of luanufatiuring which is by 

 grinding the tubes to fit the botth-s after the tubes have beeii 

 bent: IVont this clrcuniftimee, it generally hap])ens that the 

 bottles have no equal Itandiug, but are obliged to be aecom- 

 modatetl to the bend of the tubes and the fitting of the necks 

 by means of wedges and fupports put under the bottles, which 

 rontinuuUy expoTes the tubes to tlie rifque of being broken 

 during the adjulhnentof the parts. To remedy this mconve- 

 nience, when I want tubes, 1 canfe them lo be ground to fit 

 the woulfes while (iraight (Sec A, fig. 4. Plate VII.); I then 

 bend them into two angles of about 130' or 140', juil above 

 the ground itopper parts (Sec B, fig. 4.) : then taking the 

 two bottles to which the tube has been ground, and placing 



* in oiher cafes, houxver, even where g^ifes are to pafs throui;h rfitFcr- 

 cnt ii()uid:>, they could be difpenfed with, if, as Mr, Chcncvix fugi^cfted. 

 wt.tn I fhowcd him the apparatus, a fct of adaptors were provided, each 

 furnifticd with a valve, iiV.c the loweft adaptor, inftcad of the bent tu.jo now 

 attached to them. The gas evolved niigtu by this means be made to nafs 

 through any number of adaptois, which would favc yll the troui)le attend- 

 ing gFtfi tubes. The valves, however, would conlidcrably incr.afc th': 

 exptnftf. 



3 them 



